Teratocephalus sp.

The terrestrial nematode genus Teratocephalus de Man, 1876, includes at present 29 bacteria feeding species. They occur particularly on mosses and sometimes in semi-aquatic habitats world-wide (including Antarctica). Their morphology makes them easy to recognize: all are relatively small with a strongly annulated cuticle. Males are rare. Although they do not have any phasmids nor a bursa, they were often placed within the Rhabditida (=”Secernentia” or “Phasmidia”). At present they are positioned in clade 7 of the basal Chromadoria (see also van Megen et al., 2009).  

More pictures of Teratocephalus costatus Andrássy, 1958:

Teratocephalus costatus: female body
Teratocephalus costatus: female body

Teratocephalus costatus: head region with offset labial region
Teratocephalus costatus: head region with offset labial region

Teratocephalus costatus: cuticule rings 2um
Teratocephalus costatus: cuticule rings 2um
Teratocephalus costatus: pharynx, posterior part
Teratocephalus costatus: pharynx, posterior part
Teratocephalus costatus: cuticle with lateral field
Teratocephalus costatus: cuticle with lateral field
Teratocephalus costatus: vulva region
Teratocephalus costatus: vulva region
Teratocephalus costatus: tail region with anal opening
Teratocephalus costatus: tail region with anal opening

(Click on the pictures for an enlargement, © Wageningen University & Research, Laboratory of Nematology/Pictures: Hanny van Megen)